Art. XXIX.—Musci: Notes on the Genus Gymnostomum, with Descriptions of New Species.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 26, 1893, Page 296

Art. XXIX.—Musci: Notes on the Genus Gymnostomum, with Descriptions of New Species. By Robert Brown. [Read before the Philosophical Institute of Canterbury, 1st November, 1893.] Plates XXXV.-XXXVII. The genus Gymnostomum is distinguished from the other allied genera of mosses by its species being perennial, and the cellular tissue of the upper portion of their leaves being small and dense; also in the absence of a peristome. In the genus Pottia, which is closely allied to it, the peristome is also absent, but species of the latter are either annual or biennial, and the cellular tissue is large and more succulent. In all other respects these two genera are similar, having also the same habitats, and being similar in appearance, which will account for Mr. Charles Knight (in his description of certain mosses, published in vol. vii. of the “Transactions and Proceedings of the New Zealand Institute,” p. 354) placing G. areolatum in the genus Gymnostomum instead of that of Pottia, to which, from its large cell-structure, it probably belongs. These mosses are generally found on damp banks, on the ground, and are in fruit from October till February or March. Species of both genera are often seen growing on the same bank. Since the publication of the “Handbook of the Flora of New Zealand” I have discovered no record of any new species of the genus Gymnostomum excepting Mr. Knight's descriptions referred to above. It is to be regretted that fuller details of some of these mosses were not given, as it appears from the descriptions that two of them do not belong to this genus, but to other genera. I have therefore not

included them in this paper, but have left them to be placed in their proper position hereafter. There are but two species described in the Handbook—viz., G. tortile and G. calcareum. G. tortile is distinguished from all the other New Zealand species yet found by the regular incurving of the margins of its leaves. It is also a native of Britain and other parts of Europe. G. calcareum I have collected at Castle Hill on the West Coast Road, and also at the Weka Pass. It was found on wet banks, in dense, irregular pulvinate patches, often very large, fruiting sparingly. The plant I have identified as G. calcareum I have drawn on Pl. XXXV. Mr. Knight describes five species of this genus in the paper before referred to—viz., G. patulum, G. knightii, G. sulcatum, G. areolatum, and G. angustatum. He also describes a variety of G. calcareum which he has named var. intermedia. G. patulum.—There is a note attached to the description of a moss (Weissia flavipes) in Hooker's Handbook, p. 404, which states that Mr. Wilson, who examined the Auckland form of this moss very carefully, suggested that it was probably a different species from W. flavipes, on account of his finding no trace of a peristome, and proposed to name it Gymnostomum patulum. Mr. Knight does not mention whether it is this particular moss or another species which he has thus named (G. patulum). Knight's plant is described as having the mouth of the capsule closed by a membrane, and having crisp leaves. These two characters would make this plant a most distinct species; but in the figure representing the whole plant the fruitstalk is drawn twice the length of the leaves, while in the description it is described as no longer than the leaves. Also, in the enlarged drawing of a leaf (vol. vii., pl. xxviii., fig. c) it is drawn as if the margins of the leaf had a thickened border, or were either incurved or recurved, which is also not described, leaving it doubtful which is correct. G. knightii is one of the most distinct species in this genus, and is readily identified. It grows in Hagley Park, in the Domain, and round the neighbourhood of Christchurch. G. calcareum, var. intermedium.—In the enlarged figure of the leaf of this plant a thickened border is shown, which is not described. This is evidently a mistake, as G. calcareum has not a thickened margin. G. sulcatum.—This plant occupies a rather anomalous position by being placed in the genus Gymnostomum, as the furrowed capsules of this moss point to the genus Zygodon as being the proper place for it, there being a gymnostomous section in that genus which has also sulcate capsules and

small cellular tissues. I have not seen this plant, but from its description am of the opinion that it belongs to the latter genus. A reference to the figure given also confirms my idea. I do not therefore propose to treat it as a Gymnostomum. G. areolatum.—This moss is also in much the same position with regard to its genus as G. sulcatum. The large cellular tissue described as belonging to this plant, and the drawing thereof, show that it is a true member of the genus Pottia, which is composed of annual or biennial plants, having large cell-structure. I therefore propose to place this moss in the latter genus. G. angustatum.—I was under the impression that I had discovered this moss, but on closely examining my specimens I found traces of sixteen teeth, and, although it corresponded in every respect with Mr. Knight's description of G. angustatum, with the exception of these teeth, it therefore could not possibly be the same moss. The following is the proposed arrangement of the species of this genus as discovered to date:— Gymnostomum calcareum, Nees and Hornsch. " " var. intermedia, Knight. " tortile, Schwægrichen. " patulum, Knight. " knightii, Schimper. " angustatum, Knight. " pygmæum, nov. sp. " ligulatum, nov. sp. " waimakaririense, nov. sp. " magnocarpum, nov. sp. " stevensii, nov. sp. " longirostrum, nov. sp. " wrightii, nov. sp. " " var. A. Gymnostomum pygmæum, nov. sp. Plate XXXV. Plants very small, perennial, growing in dense patches. Stem extremely short, branched. Branches fastigiate, 1/32in. long. Leaves minute, erecto-patent or erect, linear-lanceolate, acuminate. Margins entire. Nerve faint, disappearing below the apex. Lower areola oblong, quadrate; upper small, crisped when dry. Perichætial leaves half as long as the upper-stem leaves, erect, entire, otherwise similar to the stem-leaves. Fruitstalk inclined, 3/16in. high. Capsule ovate, symmetrical. Mouth narrowed. Peristome none. Operculum oblique, conico-rostrate, two-thirds length of capsule. Calyptra cucullate. Hab. Damp limestone rocks, near Castle Hill. Collected March, 1891, by R. B.

Gymnostomum ligulatum, nov. sp. Plate XXXV. Plants small, perennial, growing in dense patches, darkish-green. Stem short, 1/16in., branched. Branches fastigiate, 1/16in. Leaves crowded, spreading, or erecto-patent, ligulate rounded at the apex, apiculate by the excurrent nerve, keeled. Margins entire. Nerve same colour as the leaf, excurrent. Perichætial leaves much smaller than stem ones, otherwise very similar. Fruitstalk slightly longer than the leaves. Capsule large, ovate, subsymmetrical. Operculum oblique, conic, tapering to the point, two-thirds the length of the capsule. Calyptra not found. Hab. Port Lyttelton Hills, on damp banks, fruiting from November to January. Collected, 1882, by R. B. This plant differs from G. patulum, Knight, principally in the mouth not being closed by a membrane, and in the perichætial leaves being shorter than the stem ones. Gymnostomum waimakaririense, nov. sp. Plate XXXVI. Plants small, perennial, growing in dense patches. Stem 3/16in., branched. Branches fastigiate, 1/16in. Leaves close-set, erecto-patent. Upper leaves recurving, lanceolate, sharply acuminate, semi-convolute, keeled. Margins entire. Nerve excurrent. Upper areola dense, lower oblong-quadrate. Perichætial leaves one-third longer than stem ones, linear-lanceolate, very acuminate, tapering from a broad base. Nerve excurrent. Fruitstalk ⅛in. long, shorter than the perichætial leaves. Capsule subimmersed, ovate, symmetrical. Operculum conico-rostrate, more than half the length of the capsule. Calyptra cucullate. Hab. Damp ground, among willows, at the River Waima-kariri. Collected, September, 1885, by R. B. Gymnostomum stevensii, nov. sp. Plate XXXVI. Plants small, perennial, growing in dense patches. Stem very short, branched. Branches fastigiate, 1/16in. long. Leaves closely crowded, spreading, or erecto-patent, linear-lanceolate or acuminate, semi-convolute, slightly cucullate, and incurved at the apex, keeled. Margins entire, sometimes slightly incurved. Nerve excurrent, almost apiculate. Upper areola dense, lower oblong-quadrate, crisped when dry. Perichætial leaves very long, linear-lanceolate, acuminate, nerved. Fruitstalk pale, 5/16in. long. Capsule large, oval. Operculum oblique, short, conico-rostrate. Calyptra not found. Hab. Damp banks, Port Lyttelton Hills. Collected in 1882, by R. B. This plant is conspicuous, and easily distinguished by its large capsule and long perichætial leaves. I have named

it in compliment to a member of the Institute, Joseph Stevens, Esq., of Christchurch. Gymnostomum magnocarpum, nov. sp. Plate XXXVI. Plants small, perennial, growing in dense, olive-green patches. Stem 3/16in., branched. Branches fastigiate, ⅛in. Leaves closely imbricating, spreading, or erecto-patent, slightly recurving, oblong-lanceolate, acuminate, occasionally rounded to an apiculus, concave. Margins entire, sometimes slightly incurved. Nerve excurrent. Areola, upper dense, lower oblong-quadrate, crisped when dry. Perichætial leaves shorter than the stem ones, narrow, lanceolate from a broader base, acuminate. Nerve excurrent. Fruitstalk 3/16in., pale, inclined. Capsule ovate-symmetrical. Operculum convexo-rostrate, about two-thirds length of capsule. Calyptra cucullate. Hab. Damp banks, Governor's Bay. Collected, August, 1881, by R. B. Gymnostomum longirostrum, nov. sp. Plate XXXVII. Plants small, perennial, growing in dense yellowish-green patches. Stem short, 1/16in., branched. Branches fastigiate. Leaves crowded, erecto-patent, linear-lanceolate, acuminate or apiculate, concave, keeled. Margins entire. Nerve pellucid, continuous or excurrent. Areola, lower half oblong-quadrate, upper dense, crisped when dry. Perichætial about the same length as the upper leaves, nearly erect. Fruitstalk pale, slender, inclined, ¼in. long. Capsule ovate, unsymmetrical, narrowed towards the mouth. Operculum oblique, slender, conico-rostrate, as long as the capsule, sometimes longer. Calyptra long, cucullate. Hab. Damp banks, on Port Lyttelton Hills, 1873; and in the Valley of the Clinton, 1889; fruiting from December to February. Collected by R. B. Gymnostomum wrightii, nov. sp. Plate XXXVII. Plants small, perennial, growing in dense patches. Stems 1/16in., branched. Branches 1/16in., fastigiate. Leaves ovate-lanceolate, obtuse or acute, apiculate, concave. Margins entire. Nerve excurrent. Areola, upper dense, lower oblong-quadrate, crisped when dry. Perichætial leaves longer than the stem ones, linear-lanceolate, acuminate. Nerve excurrent. Fruitstalk ⅓in. long, no longer than the leaves. Capsule very oblique. Operculum oblique, conico-rostrate, about two-thirds length of capsule. Calyptra cucullate. Hab. Damp banks, Broken River, West Coast Road, 1891. Var. A. A variety near the River Heathcote, collected by R. B. in 1882. Has a stouter operculum and the leaves longer.

(All the figures of these mosses, as well as my previous contributions in this direction, are drawn with the assistance of a camera lucida to one scale, for the purpose of greater facility of comparison.) Explanation of Plates XXXV.-XXXVII. Plate XXXV. Gymnostomum calcareum. Fig. 1. Capsule. 2. Perichætial leaves. 3. Stem leaf (lower). 4. Stem leaf (upper). Gymnostomum pygmæum. 1. Capsule. 2. Perichætial leaves. 3. Upper stem leaf. 4. Stem leaves. Gymnostomum ligulatum. 1. Capsule. 2. Perichætial leaves. 3. Stem leaves. Plate XXXVI. Gymnostomum waimakaririense. Fig. 1. Capsule. 2. Perichætial leaf. 3. Stem leaves. Gymnostomum stevensii. 1. Capsule. 2. Perichætial leaves. 3. Stem leaves (upper). Gymnostomum magnocarpum. 1. Capsule. 2. Perichætial leaf (inner). 3. Perichætial leaf (outer). 4. Stem leaves. Plate XXXVII. Gymnostomum longirostrum. Fig. 1. Capsule. 2. Calyptra. 3. Perichætial leaves. 4. Stem leaf (upper). 5. Stem leaf (lower). Gymnostomum wrightii 1. Capsule. 2. Perichætial leaf (inner). 3. Perichætial leaf (outer). 4. Stem leaves.